Transfer hydrogenation of ketones catalyzed by iridium-bulky phosphine complexes

One-pot three-step mechanically assisted synthesis and catalytic performance of tripodal metallic complexes

All-green matters. Synthesis of the ligand and metal–ligand complexes and a model catalytic oxidation reaction can be sequentially processed under solventless conditions using a planetary ball mill, via fast, high yielding and selective processes.

Strong Solvent Effects on Catalytic Transfer Hydrogenation of Ketones with [Ir(cod)(NHC)(PR3)] Catalysts in 2-Propanol-Water Mixtures

The synthesis and characterization of the new Ir(I)-complexes [IrCl(cod)(Bnmim)], [Ir(cod)(emim)(PPh3)]Cl and [Ir(cod)(Bnmim)(mtppms)] are reported. The zwitterionic complexes [Ir(cod)(NHC)(mtppms)] and Na2[Ir(cod)(NHC)(mtppts)] (NHC = emim, bmim or Bnmim; mtppms-Na and mtppts-Na3 = sodium salts of mono- and trisulfonated triphenylphosphine, respectively) were found to be effective precatalysts for transfer hydrogenation of aromatic and aliphatic ketones in basic 2-propanol-water mixtures with initial turnover frequencies up to 510 h−1 at 80 °C, and their catalytic performances were compared to those of [IrCl(cod)(NHC)] complexes (NHC = emim, bmim, Bnmim, IMes) and [Ir(cod)(emim)(PPh3)]Cl. Three of the catalysts were characterized by single-crystal X-ray diffraction. The reaction rates of the transfer hydrogenation of acetophenone and benzophenone showed strong dependence on the water concentration of the solvent, indicating preferential solvation of the catalytically active metal complexes.